GB1451670A - Electric cam selector mechanism for sewing machines - Google Patents

Abstract

1451670 Cams etc SINGER CO 13 Dec 1974 [23 Jan 1974] 53911/74 Heading F2K [Also in Division D1] A plurality of cams 50, 60, 70 and mechanism 29, 28, 27, 22 for regulating and producing a stitch pattern (in a sewing machine, see Division Dl) has means including electrical means (solenoids) for selecting which of the cams actuate the mechanism. Each cam 50, 60, 70 has a follower set 51, 61, 71 (Fig. 3A) each comprising two bell crank levers such as 515, 520, pivoted on a common pivot 90 and presenting the respective arms 513, 518 engaging respectively the respective cam (50) and member 29. The other arms of the levers are yieldably biassed into alignment by a spring 523 and when aligned present holes 516 (and 521, Fig. 3B not shown) in register so that a locking pin (525) may enter when a solenoid 524 is energised, the arms 515, 520 then being locked together so that the cam 50 may operate mechanism 29 through the fingers 514, 519. The holes 516, 521 are aligned when sufficient clearance exists between member 29 and cam valley 53 to allow the spring 523 to align the arms. To provide this clearance a 'locking' cam 80 beneath the cam stack has higher peaks 82 and lower valleys 83 than the other cams and the solenoid 824 associated with its follower levers is connected (Fig. 5 not shown) to be energised when any of the solenoids 524, 624, 724 is energised by operation of its selector switch 150, 160, or 170. At a valley 83 the follower set 81 is locked and at a peak the member 29 is swung beyond its normal position, (Fig. 2A, not shown) to allow the selected cam follower to be locked, a switch (100) being operated at the extreme position of member 29 to then de-energise solenoid 824.